1e95ba2538135af3405f62ff5404879768e168e3
[libav.git] / libavcodec / png.h
1 /*
2 * PNG image format
3 * Copyright (c) 2003 Fabrice Bellard.
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #ifndef AVCODEC_PNG_H
23 #define AVCODEC_PNG_H
24
25 #include <stdint.h>
26
27 #define PNG_COLOR_MASK_PALETTE 1
28 #define PNG_COLOR_MASK_COLOR 2
29 #define PNG_COLOR_MASK_ALPHA 4
30
31 #define PNG_COLOR_TYPE_GRAY 0
32 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
33 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
34 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
35 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
36
37 #define PNG_FILTER_VALUE_NONE 0
38 #define PNG_FILTER_VALUE_SUB 1
39 #define PNG_FILTER_VALUE_UP 2
40 #define PNG_FILTER_VALUE_AVG 3
41 #define PNG_FILTER_VALUE_PAETH 4
42
43 #define PNG_IHDR 0x0001
44 #define PNG_IDAT 0x0002
45 #define PNG_ALLIMAGE 0x0004
46 #define PNG_PLTE 0x0008
47
48 #define NB_PASSES 7
49
50 extern const uint8_t ff_pngsig[8];
51
52 /* Mask to determine which y pixels are valid in a pass */
53 extern const uint8_t ff_png_pass_ymask[NB_PASSES];
54
55 /* minimum x value */
56 extern const uint8_t ff_png_pass_xmin[NB_PASSES];
57
58 /* x shift to get row width */
59 extern const uint8_t ff_png_pass_xshift[NB_PASSES];
60
61 /* Mask to determine which pixels are valid in a pass */
62 extern const uint8_t ff_png_pass_mask[NB_PASSES];
63
64 extern void *ff_png_zalloc(void *opaque, unsigned int items,
65 unsigned int size);
66
67 extern void ff_png_zfree(void *opaque, void *ptr);
68
69 extern int ff_png_get_nb_channels(int color_type);
70
71 /* compute the row size of an interleaved pass */
72 extern int ff_png_pass_row_size(int pass, int bits_per_pixel, int width);
73
74 #endif